This invention generally relates to an apparatus for producing a highly desirable coffee product by the cup or pot; and additionally, to a prepackaged, single use cassette holding a quantity of coffee particles wherein hot water is passed through the cassette.
Prepackaged, single use cassettes of the above-described general type are known in the art, and for example, such a cassette is disclosed in U.S. Pat. No. 4,446,158. This reference discloses a coffee brewing receptacle having an opening in the bottom thereof, and a disposable, single use coffee container and filter unit that is designed to be held in the bottom opening of that coffee brewing receptacle. This coffee unit, in turn, comprises a frame, top and bottom filters secured to and covering the top and the bottom, respectively, of the frame, and individual quantities of coffee held in compartments formed inside the frame.
In use, the coffee container and filter unit is tightly secured against a lower flange of the coffee brewing receptacle, with the coffee unit extending across the bottom opening of that receptacle. This receptacle is then placed on top of a cup, and hot water is poured through the coffee brewing receptacle and the coffee unit secured across its bottom opening. The hot water is flavored as it flows through the coffee unit, producing coffee, which passes into the cup below the coffee unit. With the above described apparatus, it is sometimes difficult to secure the coffee container and filter unit in, and subsequently to remove that unit from, the brewing receptacle.
U.S. Pat. No. 3,937,134 discloses an apparatus for making coffee by percolation of preheated water. This apparatus comprises a reservoir adapted to receive water, and an extraction chamber adapted to receive a ground coffee tablet, which will expand or swell when percolated. A perforated wall separates the reservoir from the extraction chamber; and, in use, water flows or trickles from the reservoirs, through the perforated wall and into the extraction chamber through gravity.
U.S. Pat. No. 3,823,656 discloses a single-use, throw-away coffee brewing apparatus, including a filtering body adapted to receive a liquid and a coffee containing cartridge or capsule secured to the bottom of that body, A special locking design is used to hold the coffee cartridge to the filtering body to prevent relative movement therebetween and to form a seal between the coffee cartridge and the filtering body.
A number of difficulties have arisen in using prior art devices employing single-use, prepackaged coffee cassettes or cartridges to brew small quantities of coffee. For instance, often these devices do not consistently produce coffee with the same strength, the devices may take an undesirable length of time to make coffee, or the devices may be costly to make or use.